A bruise is a condition caused by distress to tissue that causes capillaries to break under the skin, allowing blood to escape and build up. As time progresses, blood seeps into the surrounding tissues, causing the bruise to darken and spread. The damaged capillary endothelium releases endothelin, a hormone that causes narrowing of the blood vessel to minimize bleeding. As the endothelium is destroyed, the underlying von Willebrand factor is exposed and initiates coagulation, which creates a temporary clot to plug the wound and eventually leads to restoration of normal tissue.
During this time, larger bruises may change color due to the breakdown of hemoglobin from within escaped red blood cells in the extracellular space. The striking colors of a bruise are caused by the phagocytosis and sequential degradation of hemoglobin to biliverdin to bilirubin to hemosiderin, with hemoglobin itself producing a red-blue color, biliverdin producing a green color, bilirubin producing a yellow color, and hemosiderin producing a golden-brown color. As these products are cleared from the area in the normal healing process of the body, the bruise disappears. Often the underlying tissue damage has been repaired long before this process is complete.
Because the color produced by bruising is cosmetically unappealing, consumers want to minimize the appearance by application of cosmetic products. Some cosmetic products provide color to the skin to hide the bruise. This approach does not help correct the problem, but rather simply covers it up. Providing color to the skin is not only is a short-term approach, it can also lead to unacceptable consumer response if the color in uneven.
The other approach is to provide a topical product that improves the appearance of the bruise. While not wanting to be held to one specific theory, the best topical product candidates will allow for the re-establishment of the homeostatic state that was present before the bruise-causing incident. This results in an amelioration of the appearance of the bruise. Specifically, the skin needs to be returned as quickly as possible to the natural state of water balance present before the incident that caused the bruising. For the purposes of this invention, references to “skin” encompass the epidermis, dermis, and proximal tissues below the skin where a bruise may appear.
There are two known methods of returning the skin to its normal state of hydration: (a) topical application of occlusives (water insoluble materials work by forming a thin film on the surface of the skin to prevent any loss of moisture, the best known of these is Vaseline); and, (b) humectants which are materials that are water soluble and attract water from the air to moisturize the skin.
One class of important occlusives is triglycerides. Triglyceride is an ester derived from glycerol and three fatty acids. They are the main constituents of vegetable oil and animal fats. As one applies oily materials (occlusives) to the external layers of the skin, the skin becomes softer and more pliable. This reduces evaporation. These materials inhibit transepidermal water loss (keep water in). They are water insoluble materials.
Humectants, like glycerin, attract water to the skin. These materials are very water-soluble.
The problem with these two approaches is that they have heretofore been mutually exclusive; that is, if only a humectant is used to attract water to the skin, it can too easily be removed from the skin by water. Occlusive materials, along, block the hydrating properties we require to ameliorate the appearance of bruises.
To further thwart the search for a truly multifunctional approach, oil and water do not mix. This lack of solubility makes the possibility of formulating a truly multi-faceted formulation to reduce the appearance of bruises impossible.
U.S. Pat. No. 7,078,056 is typical of the state of the art. It states, “The present invention concerns a method of treating a patient to attenuate, and in some cases eliminate, symptoms (e.g., pain, inflammation, bruising, etc.) normally caused or potentiated by the activation of the nociceptive system through the use of a composition including at least a hydrophilic foam substrate, a hydrophilic agent capable of absorbing water, and a wetting agent to the surface of the skin. The composition is applied to the surface of the skin in an amount and at a location sufficient to attenuate the response of the nociceptors to noxious stimuli.” The key to this reference is it uses a totally hydrophilic treatment system, clearly avoiding hydrophobic materials that lock in the moisture and smooth the damaged skin.
There has been a long felt need to produce a composition that can be used to ameliorate the appearance of bruises.